Acting Chief Inspector Kevin Waring, of Sunderland Area Command, said: “We are working closely with Trading Standards to identify and visit premises selling these substances and will take any action necessary to ensure the safety of the public.

“In both these cases the substance taken appears to have been called Annihilation, Annihilator or some variation on that name.

“It may be being sold as a herbal incense and must not be consumed.”

According to one website, Annihilation is a “new incense with an EXPLOSIVE strength!

“From the Mary Joy family, this new head-blowing herbal incense Annihiliation has arrived with a BOOM!”

Officers are now carrying out enquiries to establish where the substances came from.

Detective Chief Inspector Ged Noble said: “We want people to be aware of the dangers of taking drugs, including so called ‘legal highs’ and medication not prescribed for them.

“I would like to stress that the use of legal high drugs is not safe and can kill or have a devastating impact on people’s health.